I bought of 134 with a dye in it. The directions said to introduce it to the system in liquid form, i.e., the can upside down. But then it said to use a throtteling device or the compressor would be damaged. So, is this true? Do I really need such a device? And if so, where do I get one and how much is it?

Thanks

Because the liquid is introduced into the accumulator, there is a small measure of protection. However, I would invert the can periodically for very short periods of time to make sure the dye is introduced. If you notice any change in compressor noise when doing so, stop and charge with gas. The instructions to use dye probably are for the purpose of getting the dye into the system. It probably won't leave the can in gas form.
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Chris Herbst, near Chicago.

I said:
"The instructions to use dye probably are for the purpose of getting the dye into the system."

I meant:
The instructions to charge upside down are probably for the purpose of introducing dye into the system.